Which is funny, because we actually built a pretty much complete nuclear power plant, Zwentendorf. It‘s now a unique museum.
A vote of just 50.47 % ruined our radiant future...
Also we do have one research reactor left right in the city. I was blessed enough to visit it once.
There really should be a rule that important decisions can't pass with a tiny majority
There are at least two major problems with such a rule:
(1) On an important question, “yes” and “no” are both important decisions.
(2) Who decides what is “important”?
You can make a rule that is closer to “you can’t make specific kinds of deviations from the status quo without a supermajority vote”, but that’s…very different from “important decisions”.